Another gene found for Alzheimer's disease
A genetic defect could be involved not only in the early but also in the late form of Alzheimer's disease. This is the result of an international study in which 14 institutes in North America, Europe and Asia took part. The researchers report that variations in the SORL1 gene are linked to the formation of amyloid plaques - the protein deposits in the brain of those affected that are characteristic of this degenerative disease.
The scientists led by Richard Mayeux from Columbia University, Lindsay Farrer from Boston University and Peter St. George-Hyslop from the University of Toronto identified 29 variants of the gene that are linked to the occurrence of the disease. However, they did not determine the individual genetic deviations, but only the regions in which they could lie. In blood samples, the researchers found that the SORL1 content in he althy people was at least twice as high as in Alzheimer's patients. This was associated with a lower production of amyloid beta fragments in the he althy compared to the Alzheimer's disease. One should not forget, however, that other genetic and other factors also influence this process, the researchers warn.
Previous studies had already identified three genes that appear to play a role in the early form of Alzheimer's dementia and one that may be a risk factor in the later form. (bf)
